The present invention relates to an analyzing apparatus, and more particularly to an analyzing apparatus suitable for analyzing a liquid sample.
In recent years, biochemical analyzing apparatuses and immunity analyzing apparatuses have continuously operated for a long time because of centralization of examination and increase in analyzed items. During such a long operation, there occur evaporation of samples and reagents, and mixing of atmospheric dust into the samples and the reagents since it is natural for the samples and the reagents to be left in the atmosphere for a long time. In particular, change in concentration of a reagent cannot be neglected because it affects the analyzed result. It is, therefore, important to prevent the evaporation at least.
In the past, there have been generally few biochemical analyzing apparatuses and immunity analyzing apparatuses which take measures to actively prevent evaporation of the reagent in the apparatus. Therefore, when a reagent is used for a long time, scheduled calibrations with a comparatively short period are required since evaporation of the reagent is inevitable, and, accordingly, change in the concentration affects the accuracy of analysis.
A reagent supplying apparatus having a measure to prevent evaporation of reagent is disclosed in U.S. Pat. No. 4,455,280. The reagent supplying apparatus comprises a turntable supporting a plurality of reagent vessels, and caps attached to the turntable itself in one-to-one correspondence to the reagent are arranged on the turntable. In this conventional technology, the evaporation of liquid reagent is prevented by capping a reagent vessel with a spring-loaded cap.
In an apparatus in which a vessel and a cap are separately formed and the cap is attached to the apparatus in advance as in the reagent supplying apparatus of the U.S. Pat. No. 4,455,280, one-to-one correspondence between the vessel and the cap having the same content is always necessary because there is a possibility of carry-over due to attaching of the content in a vessel to a cap if the vessel is set at an arbitrary position to the cap arranged in a given position in the apparatus every time the vessel is set to the apparatus. This eliminates the freedom of setting vessel position.
Further, if the vessels and the caps are formed separately, an operator has to attach and detach the vessel caps every time the vessels are set to an apparatus or kept in a storage.